I'd like to build a dry area under my deck. My neighbor has a product, (called Dry Below) that he tested for the OEM a couply years ago. It is placed in between the joists and the theory is to channel all the water passing through the deck to an end. The product itself is a failure without modifications, i.e. my neighbor had to remove his decking and flash each joist. My question: Is there a product that I can purchase that will allow me to keep my under deck dry without modification to the decking?